Fig. 5.  A represents mean (SD) static lung compliance at baseline and over the course of the protocol in the presence of antibiotic therapy in normocapnia (n = 10) and hypercapnic acidosis (HCA; n = 10).  B represents a stereologic assessment of the extent of histologic injury in established  Escherichia coli pneumonia in the absence of antibiotic therapy. The  P value refers to the overall comparison between HCA and normocapnia.